303.18 EMERGENCY AND EXPERIMENTAL REGULATIONS.
   The Chief of Police by and with the approval of Council is hereby empowered to make regulations necessary to make effective the provisions of the Traffic Code and to make and enforce temporary or experimental regulations to cover emergencies or special conditions. No temporary or experimental regulation shall remain in effect for more than ninety days.
   The Chief of Police may test traffic control devices under actual conditions of traffic.
(1947 Code §19.10)